基于GNSS掩星资料对往返平飘式探空温度观测的质量评估  

The Evaluation of Return Radiosonde Temperature using GNSS Radio Occultation Retrievaled Temperature

作　　者：容娜 杨胜朋[1,2] 王金成 王丹[3,4] RONG Na;YANG Shengpeng;WANG Jincheng;WANG Dan(College of Atmospheric Sciences,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Joint Center for Data Assimilation Research and Applications,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Numerical Weather Prediction Center of China Meteorological Administration,Beijing 100081,China;National Meteorological Center,Beijing 100081,China)

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]南京信息工程大学资料同化研究与应用联合中心,江苏南京210044 [3]中国气象局数值预报中心,北京100086 [4]国家气象中心,北京100086

出　　处：《高原气象》2023年第1期221-232,共12页Plateau Meteorology

基　　金：国家重点研究发展计划项目(2018YFC1506205);青海省科技厅创新平台专项(2019-ZJ-T03)。

摘　　要：同化应用一种新型观测资料前,对新型观测资料开展质量评估必不可少。为了实现往返平飘式探空资料的同化应用,基于GNSS掩星观测资料和ERA-Interim再分析资料,分析评估了往返平飘式探空“上升-平飘-下降”三段观测中温度资料的质量。在平飘段使用Cressman算法对其插值并与掩星干温度进行对比,发现平飘段日间受太阳辐射的加热影响,其温度存在明显的正偏差,夜间则表现为弱的温度负偏差。采用ERA-Interim再分析资料与掩星、往返平飘式探空平飘段资料做交叉对比,进一步验证了上述结果。分析了平飘段与掩星干温度偏差随地方时的变化情况,发现了日间温度偏差的平均范围为7~10℃,夜间为-4~0℃。参照WMO对于温度不确定度的规定,日间温度观测接近边界目标6℃,夜间则符合突破目标。往返平飘式探空上升(下降)段与掩星湿温度资料具有较好的一致性,上升段T_(RS)-T_(RO)的均值范围为-1~1℃,下降段在13 km以下时也为-1~1℃,13 km以上增加到1~3℃。整体而言,往返平飘式探空上升(下降)段温度资料的质量较好,下降段对探空观测具有时空加密的作用,观测质量满足数值天气预报和其他领域的应用。It is necessary to evaluate the quality of a new type of observation data before using it for data assimi‐lation.Based on GNSS radio occultation (RO) and ERA-Interim reanalysis data,the quality of temperature in the ascent,drift and descent stage of return radiosonde has been analyzed and evaluated.In the drift stage using the method of Cressman to interpolate the temperature of return radiosonde and compare with the dry temperation(Tdry) of RO,the results show that there is an obvious positive deviation in return radiosonde temperature data caused by the heating of solar radiation in the daytime and a weak negative deviation at night.A further verify of the above results by comparing between ERA-Interim reanalysis,RO T_(dry) and return radiosonde.The average temperature bias between the drift stage and RO T_(dry) evoluting with local time ranges is 7~10℃in daytime and-4~0℃at night.The results show that the precision of night temperature observations of return radiosonde reach‐es the breakthrough target defined by the WMO(world meteorological organization).The temperature between the ascent and descent stages in return radiosonde and the wet temperation (T_(wet)) of RO shows a good consisten‐cy,which the mean bias ranges is-1~1℃in ascent stage as well as below 13 km in descent stage,this bias slightly increases and ranges is 1~3℃above 13km in descent stage.On the whole,the quality of the temperature data in the ascending (descending) stage of return radiosonde is better than the drift stage observations.Mean‐while,the descend stage has the function of space-time encryption for the radiosonde observation,and the data quality meets the application of numerical weather forecast and other analysis study fields.

关 键 词：往返平飘式探空 探空加密 交叉检验 温度偏差 

分 类 号：P405[天文地球—大气科学及气象学]